Projection television system

A projection colour television system having an improved resolution and luminance comprises red, green and blue colour emitting tubes, the electron beams of which are focused onto their respective screens. In order to compensate for the strong saturation of the blue phosphor, and simultaneously to take advantage of the relatively fast decay of this phosphor, the blue colour emitting tube is a single gun, multispot display tube. The increase in light output obtainable from the blue colour emitting tube is matched by providing interference filters in the red and green colour emitting display tubes and optionally in all three red, green and blue emitting tubes.